Porsche 911 MOT failure rate and common faults
34,056 Porsche 911 cars aged 3 to 20 took their MOT in 2025, and 8.0% failed at the first attempt. An average car of the same age failed 30.2% of the time, which makes the Porsche 911 74% less likely to fail than the typical car on the road. Here is what fails, and which years to look for.
8.0%
failed first time
34,056 MOT tests in 2025
-74%
vs same age average
average car of this age mix: 30.2%
1 of 208
age adjusted rank
among cars; 1 fails least
27.2
dangerous defects per 1,000
same age average: 109.5
What fails on a Porsche 911 MOT
Failure items recorded per 1,000 tests, by part of the car, set against an average car with exactly the same spread of ages. A figure well above average is a weak spot worth checking before you buy.
The most common Porsche 911 MOT failures
The individual failure items testers recorded most often, per 1,000 tests.
| Failure item | Area | Per 1,000 tests |
|---|---|---|
| Headlamp aim: too high | Lights and electrics | 10.5 |
| Tyres: has a cut in excess of the requirements deep enough to reach the ply or cords | Tyres | 8.7 |
| Tyres: has ply or cords exposed | Tyres | 7.9 |
| Drive shafts: constant velocity boot split or insecure, no longer prevents the ingress of dirt | Body, chassis, exhaust and drive shafts | 7.7 |
| Tread depth below requirements of 1.6mm | Tyres | 7.5 |
| Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits | Engine, emissions and leaks | 6.8 |
| Registration plates: does not conform to the specified requirements | Number plates and VIN | 5.0 |
| Rigid brake pipes: excessively corroded | Brakes | 4.7 |
| Wipers: does not clear the windscreen effectively | Windscreen, wipers and mirrors | 3.9 |
| Headlamp aim: too low | Lights and electrics | 3.2 |
Porsche 911 MOT failure rate by year
Every car fails more often as it ages, so each registration year is compared with the average for all cars of the same age. Years with fewer than 500 tests are left out.
| First registered | Tests | Failed | Same age average | Average mileage |
|---|---|---|---|---|
| 2022 | 2,570 | 4.6% | 11.4% | 10,200 |
| 2021 | 1,687 | 3.0% | 12.8% | 14,500 |
| 2020 | 1,501 | 4.3% | 14.1% | 20,000 |
| 2019 | 2,299 | 5.3% | 16.5% | 22,800 |
| 2018 | 2,149 | 5.3% | 19.1% | 21,600 |
| 2017 | 1,883 | 6.5% | 21.8% | 27,800 |
| 2016 | 1,703 | 6.0% | 25.1% | 31,600 |
| 2015 | 1,734 | 5.6% | 28.1% | 34,800 |
| 2014 | 1,530 | 6.5% | 31.4% | 37,300 |
| 2013 | 1,275 | 4.9% | 34.3% | 45,900 |
| 2012 | 1,543 | 6.6% | 36.6% | 50,700 |
| 2011 | 1,307 | 8.5% | 38.8% | 46,500 |
| 2010 | 1,722 | 9.5% | 40.7% | 51,000 |
| 2009 | 1,468 | 10.1% | 41.8% | 61,100 |
| 2008 | 1,808 | 10.7% | 42.9% | 60,100 |
| 2007 | 2,425 | 12.7% | 42.7% | 61,700 |
| 2006 | 2,701 | 13.3% | 43.0% | 69,800 |
| 2005 | 2,751 | 13.9% | 42.4% | 72,600 |
Advisories to look for in a Porsche 911's MOT history
An advisory is a tester's warning that something is wearing but has not failed yet. These are the ones written most often on the Porsche 911, per 1,000 tests. If the car you are looking at has one of these, ask whether it has been fixed since.
- Tread depth: worn close to legal limit/worn on edge126.1
- Tyres: slightly damaged/cracking or perishing71.3
- Rigid brake pipes: corroded, covered in grease or other material59.5
- Brake discs: worn, pitted or scored, but not seriously weakened57.0
- Engine oil leaks: leak, but not excessive16.5
- Ball joint has slight play13.8
Checking a used Porsche 911 before you buy
The Porsche 911 has no part of the car that fails well above average for its age, so check the areas that fail most often overall.
Tyres
Check the tread across the full width of every tyre, inner edge included. Uneven wear points to worn suspension or out of line steering geometry.
Lights and electrics
Walk round the car with every light on: headlights on dip and main beam, indicators, brake lights, fog lights and the number plate lamp. A pattern of electrical faults costs more than a bulb.
Brakes
Look through the wheel spokes at the discs for a deep lip or scoring, check the handbrake holds the car on a slope, and feel for a pull to one side when braking hard.
Averages only take you so far. The specific car's MOT history shows whether it has already failed on any of these, how often advisories were ignored, and whether the mileage climbs steadily from test to test. Read our guide to reading a car's MOT history before you go to view it.
Porsche 911 MOT questions
What is the Porsche 911 MOT failure rate?
8.0% of Porsche 911 cars failed their first MOT test of 2025, from 34,056 tests on vehicles aged 3 to 20. An average car with the same age mix failed 30.2% of the time, so the Porsche 911 was 74% less likely to fail.
What fails most often on a Porsche 911 MOT?
Tyres caused the most failure items, at 34 per 1,000 tests. The single most common failure item was "Headlamp aim: too high", recorded 10.5 times per 1,000 tests.
Which Porsche 911 year has the best MOT record?
Measured against cars of the same age, 2013 registrations did best: 4.9% failed against an average of 34.3% for cars that age. Older cars always fail more often, so compare a year with its age group rather than with newer cars.
Does this tell me whether a particular Porsche 911 will pass?
No. These are averages across every Porsche 911 tested in 2025. The car in front of you has its own record: its full MOT history shows every pass, failure and advisory it has had, and it is free to view by registration.
Other Porsche models
- Porsche Macan9.3% failed
- Porsche Cayenne14.3% failed
Ranked close to the Porsche 911
- Lexus NXrank 3
How these figures are calculated
Source: DVSA Anonymised MOT tests and results, 2025 release. We count first tests of cars and small vans (class 4) aged 3 to 20, so a car that fails and is retested is counted once. A failure includes faults fixed and passed within the same visit. The same age average weights the national failure rate for each age by how many Porsche 911 cars of that age were tested, so a model is never penalised for having an older fleet. Make and model are as recorded at the test; trim levels are combined. Full method and rankings.
Contains public sector information licensed under the Open Government Licence v3.0.